Some of our recent studies of the structure and mechanical properties of a special type of nanocomposite are reviewed here. In silica-latex systems, a latex film with silica inclusions is formed from a colloidal solution of both components. During drying of the solution, the formation of silica domains can be controlled via the physico-chemical properties of the solution. Well-defined silica aggregates embedded in a polymer matrix can be generated, and the mechanical properties of the resulting nanocomposite have been shown to be directly correlated to the average structure.